Grooved structural element

ABSTRACT

A structural element has elongated, parallel, transverselyspaced grooves which can accommodate the edges of transverselyspaced panels. That structural element coacts with other similar structural elements to constitute a plural-sided frame which has substantially-continuous, elongated, parallel, transverselyspaced, inwardly-directed grooves. A plurality of panels have their upper and lower edges extending into and held by one of those elongated, parallel, transversely-spaced, inwardly-directed grooves to define a structural plane; and a further plurality of panels have their upper and lower edges extending into and held by the other of those elongated, parallel, transversely-spaced, inwardly-directed grooves to define a second structural plane which is spaced transversely from the first structural plane. Connector members of generally H-shaped cross section have grooves which accommodate the side edges of the first plurality and second plurality of panels and which prevent transverse movement of those side edges relative to each other and relative to those structural planes.

United States Patent [1 Edwards 11] 3,821,868 1 1 July 2, 1974 GROOVED STRUCTURAL ELEMENT [75] Inventor: Lindell N. Edwards, St. Louis, Mo. [73] Assignee: Universal Modular Structures, Inc.,

St. Louis, Mo.

[22] Filed: Jan. 31, 1972 [21] App]. No.: 222,113

[52] US. Cl. 52/241, 52/282 [51] Int. Cl E04b 2/60 [58] Field of Search 52/241, 242, 272, 280,

[56] References Cited UNITED STATES PATENTS 2,079,635 5/1937 Sharp 52/241 2,931,468 4/1960 Keller 52/481 X 2,962,133 11/1960 Kivett et a1. 52/241 X 3,010,547 11/1961 Foster 52/731 X 3,125,194 3/1964 Kimmel et a1 52/282X 3,125,785 3/1964 Conville 52/238 3,190,408 6/1965 Petterson..... 52/282 X 3,293,813 12/1966 Emmons et a 3,310,926 3/1967 Brandreth et al 3,316,041 4/1967 3,348,349 10/1967 3,487,598 l/l97O Lopina 52/241 X 3,553,915 l/l971 Passovoyn 52/241 X Primary Examiner-Price C. Faw, Jr.

[ 5 7 ABSTRACT A structural element has elongated, parallel, transversely-spaced grooves which can accommodate the edges of transversely-spaced panels. That structural element coacts with other similar structural elements to constitute a plural-sided frame which has substantially-continuous, elongated, parallel, transversely-spac'ed, inwardly-directed grooves. A plurality of panels have their upper and lower edges extending into and held by one of those elongated, parallel, transversely-spaced, inwardly-directed grooves to define a structural plane; and a further plurality of panels have'their upper and lower edges extending into and held by the other of those elongated, parallel, transversely-spaced, inwardly-directed grooves to define a second structural plane which is spaced transversely from the first structural plane. Connector members of generally l-l-shapedcross section have grooves which accommodate the side edges of the first plurality and second plurality of panels and which prevent transverse movement of those side edges relative to each other and relative to those structural planes.

3 Claims, 32 Drawing Figures GROOVED STRUCTURAL ELEMENT This invention relates to improvements in grooved structural elements. More particularly, this invention relates to improvements in grooved structural elements which can be combined with panels to form a structure.

It is, therefore, an object of the present invention to provide an improved grooved structural element which can be combined with panels to form a structure.

SUMMARY OF THE INVENTION The structural element provided by the present invention .has elongated, parallel, transversely-spaced grooves which can accommodate the edges of transversely-spaced panels. That structural element coacts with other similar structural elements to constitute a plural-sided frame which has substantially-continuous, elongated, parallel, transversely-spaced, inwardlydirected grooves. A plurality of panels have their upper and lower edges extending into and held by one of those elongated, parallel, transversely-spaced,inwardly-directed grooves to define a structural plane; and a further plurality of panels have their upper and lower edges extending into and held by the other of those elongated, parallel, transversely-spaced, inwardlydirected grooves to define a second structural plane which is spaced transversely from the first structural plane. Those structural elements coact with those pan els to define a sturdy and rugged structure. It is, therefore, an object of the present invention to provide a structural element which has. elongated, parallel, trans versely-spaced grooves which can accommodate the edges of transversely-spaced panels.

Connector members of generally I-I-shaped cross section have sets of elongated, parallel, transverselyspaced grooves at one of the faces thereof and have further sets of elongated, parallel, transversely-spaced grooves at the opposite faces thereof. The grooves of the first set of elongated, parallel, transversely-spaced grooves of each connector member are in register with the grooves of the further set of elongated, parallel, transversely spaced grooves of that connector member; and hence the side edges'of the first plurality and second plurality of panels are held in alignment with each other and against transverse movement relative to each other by the first and further sets of grooves in the con.-

nector members of generally I-I-shaped cross section, It

is, therefore, an object of the present invention to provide a connector member of generally I-I-shaped cross section which has a set of elongated, parallel, transversely-spaced grooves at one of the faces thereof and which has a further set of elongated, parallel, transversely-spaced grooves at the opposite face thereof.

One preferred embodiment of grooved structural element provided by the present invention has an elongated passage therein which can serve as a duct for electrical elements or insulated pipes. As a result, that grooved structural element can perform the dual functions of holding the edges of panels of spaced structural planes and also of accommodating electrical elements or insulated pipes. It is, therefore, an object of the present invention to provide a grooved structural element that has an elongated passage therein which can serve as a duct for electrical elements or insulated pipes. Other and further objects and advantages of the present. invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description, several preferred embodiments of the present invention are shown and described but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and that the invention will be defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWING In the drawing, FIG. 1 is a perspective view'of two abutting walls which include grooved structural elements provided by the present invention,

FIG. 2 is a sectional view, on a larger scale, through the walls of FIG. 1, and it is taken along the plane indicated by the line 22 in FIG. 1,

FIG. 3 is a sectional view, on the scale of FIG. 2, through one-of the walls in FIG. 1, and it is taken along the plane indicated by the line 3-3 in FIG. 1,

FIG. 4 is another sectional view, on the scale of FIG. 2, through the one wall of FIG. 1, and it is taken along the plane indicated by the line 44 in FIG. 1,

FIG. 5 is a horizontal section, on a scale intermediate those of FIGS. 1 and 2, through a further grooved structural element provided by the present invention,

FIG. 6 is a horizontal section, on the scale of FIG. 5, through a portion of a structure which incorporates another grooved structural element provided by the present invention,

FIG. 7 is a horizontal section, on a scale larger than that of FIG. 2, through a portion of the structure shown in FIG. 6,

FIG. 8 is a vertical section, on the scale of FIG. 5, throughportions of a floor, a ceiling, and a wall of a room made from grooved structural elements of the present invention,

FIG. 9 is a horizontal section, on the scale of FIG. 5, through a further wall including grooved structural elements of the present invention,

FIG. 10 is a perspective view, on the scale of FIG. 2, of the upper part of one of grooved structural elements of FIG. 2,

FIG. 11 is a perspective view, on'the scale of FIG. 2, of the upper part of anotherof the groovedstructural elements of FIG. 2,

FIG. 12 is a vertical section, on the scale of FIG. 2, through a portion of a grooved structural element and through a portion of 'a plural-section panel which could be used in forming a wall,

FIG. 13 is a perspective view, on the scale of FIG. 1, of a corner defined bytwo walls,

FIG. 14 is a perspective view, on a scale intermediate those of FIGS. 1 and 2, of the upper end of the corner fitting used in the wall of FIG. 13,

FIG. 15 is asectional view, on a scale somewhat larger than that of FIG. 14, through one of the walls of FIG. 13, and it is taken along the plane indicated by the line 15-15 in FIG. 13,

FIG. 16 is a sectional view, on the scale of FIG. 15,

through both of the walls of FIG. 13, and it is taken along the plane indicated by the line 1616 in FIG. 13,

FIG. 18 is a perspective view, on a scale smaller than that of FIG. 1, of an A-frame building which is made in accordance with the principles and teachings of the present invention,

FIG. 19 is a sectional view, on the scale of FIG. 15, through a portion of the A-frame building of FIG. 18, and it is taken along the plane indicated by the line 19-19 in FIG. 18,

FIG. 20 is a sectional view, on the scale of FIG. 15, through another portion of the A-frame building of FIG. 18, and it is taken along the plane indicated by the line 20-20 in FIG. 18,

FIG. 21 is a sectional view, on the scale of FIG. 15, through a further portion of the A-frame building of FIG. 18, and it is taken along the plane indicated by the line 2l21 in FIG. 18,

FIG. 22 is a sectional view, on the scale of FIG. 15, and it is taken along the broken plane indicated by the broken line 22-22 in FIG. 21,

FIG. 23 is a sectional view, on the scale ofFIG. 15, through a still further portion of the A-frame building of FIG. 18, and it is taken along the plane indicated by the line 2323 in FIG. 18,

FIG. 24 is a horizontal section, on the scale of FIG. 16, through a corner fitting which generally resembles the corner fitting of FIG. 14,

FIG. 25 is a perspective view of the upper end of a structural element which can be positioned between the panels of a wall, ceiling, or floor made in accordance with the principles and teachings of the present invention,

FIG. 26 is'a horizontal section, on the scale of FIG.

16, through a wall which includes the grooved structural element of FIG. 25 and a grooved structural element which closelyresembles the grooved structural element of FIG. 10, and it shows I .-shaped braces securing those grooved structural elements to an underlying horizontally-directed grooved structural element,

FIG. 27 is a perspective view, on a scale larger than that of FIG. 16, of one of the L-shaped braces in FIG. 26,

FIG. 28 is a horizontal section, on the scale of FIG. 16', through a further grooved structural element provided by the present invention,

FIG. 29 is a horizontal section, on the scale of FIG. 16, through two grooved structural elements which coact with panels to define the corners of adjacent walls,

FIG. 30 is a horizontal section, on the scale of FIG. 16, through two further grooved structural elements which coact with panels to define the corners of adjacent, walls,

FIG. 31 is a horizontal section, on the scale of FIG. 16, through a grooved structural element which connects a wall at right angles to an intermediate portion of a second wall, and

FIG. 32 is a horizontal section, on the scale of FIG. I

16, through a comer fitting which is assembled from four separate elements.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring particularly to FIGS. l-4 the numeral 20 generally denotes a wall which includes grooved structural elements that are made in accordance with the principles and teachings of the present invention. The numeral 22 generally denotes a second wall which is disposed at right angles to the wall 20, and which also includes grooved structural elements that aremade in accordance with the principles and teachings of the present invention. The numeral 24 generally denotes a corner fitting which is a metal extrusion; and the cross section of that corner fitting is shown by'FIG. 2. That corner fitting has a tubular portion 26 which is essentially square in cross section; and it has a connecting portion 28 that is provided with internalribs 30, and it has a connecting portion 36 that is provided with internal ribs 38. The ribs 30 are spaced a short distance away from one of the four sides of the tubular portion 26 of the corner fitting 24; and those ribs are in register with each other. The ribs 38 are spaced a short distance away from another of the four sides of the tubular portion 26 of the corner fitting 24; and those ribs are in register with each other.

The connecting portion 28 is tubular and is rectangular in cross-section; and the area defined by that connecting portion is considerably smaller than the area defined by the tubular portion 26. Similarly, the connecting portion 36 is tubular and is rectangular in cross section; and the area defined by that connecting portion is considerably smaller than the area defined by the tubular portion 26. An elongated groove 32 is provided at the outer face of the connecting portion 28, and that groove extends longitudinally along that face. An elongated groove 34 is provided at that same face; and that groove extends longitudinally along that face. The grooves 32 and 34 are located adjacent the opposite sides of the outer face of the connecting portion 28, as shown by FIG. 2, and those grooves are parallel to each other. As a result, the grooves 32 and 34 constitute a set of elongated, parallel, transversely-spaced grooves on the corner fitting 24. An elongated groove 40 is provided at the outer face of the connecting portion 36, and that groove extends longitudinally along that face. An elongated groove 42 is provided at that same face; and that groove extends longitudinally along that face. The grooves 40 and 42 are located adjacent the opposite sides of the outer face of the connecting portion 36, as shown by FIG. 2, and those grooves are ends of the grooves 32 and 34 are cut away at an angle of 45 to provide a mitered lower left-hand corner for the corner fitting 24. The upper end of; the connecting portion 36 of the corner fitting 24 and the upper ends of the grooves 40 and 42 are cutaway at an angle of 45 to provide a mitered upper right-hand corner for that corner fitting. The lower end of the connecting portion 36 and the lower ends of the grooves 40 and 42 are cut away at an angle of 45 to provide a mitered lower right-hand corner for the corner fitting 24.

A grooved structural element is denoted by the numeral 44 in FIGS. l-3 and 11; and it preferably is formed as a metal extension. That grooved structural element is shown in FIG. 11 before the ends thereof are- As a result, those grooves constitute a set of elongated,

parallel, transversely-spaced grooves on the grooved structural element 44.

The outer face of the side 45 of the grooved structural element 44 is shown as being interrupted by knurling; but it could beinterrupted by grooves, ribs, pockets, projections or the like. The interrupting of that outer face is desirable where that outer face is to be secured to an underlying surface by cement, adhesive, mastic, grout or the like. For example, where the outer face of the side 45 of the grooved structural element 44 is set in engagement with a floor, as shown in FIGS. 1-3, the interruption of that outer face will enable cement, adhesive, mastic, grout or the like, placed between that outer face and that floor, to hold that grooved structural element against shifting relative to that floor.

In any instances where the outer face of the side 45 of the grooved structural element 44 was not to be secured to anything, that outer face could be left free of interruption, or it could be suitably ornamented by forming a pleasing design on it. Similarly, the other outer faces of that grooved structural element, and the outer faces of various of the other grooved structural elements of the present invention, could be suitably ornamented by forming pleasing designs on them.

The numeral 58 denotes a further grooved structural element; and that grooved structural element will preferably have the same cross sectionas the grooved structural element 44 in FIG. 11. Further, the numeral 66 denotes a grooved structural element at the bottom of the wall 22 in FIG. 1; and that grooved structural element will preferably have the same cross section as the grooved structural element 44 in FIG. 1']. As indicated by FIG. 1, the ends of the grooved structural elements 44, 58 and 66 are mitered; and one of the mitered ends of the grooved structural element 44 abuts the mitered lower left-hand comer of the corner fitting 24, while one of the mitered ends of the grooved structural element 66 abuts the mitered lower right-hand corner of the corner fitting 24. Consequently, the, groove 32 of the corner fitting 24 will be in register with and will abut the outer groove 48 of the grooved structural element 44, the groove-34 of that corner fitting will be in register with and will abut the inner groove 48 of that grooved'structural element, the groove 40 of that corner fitting will be in register with and will abut the inner groove of the grooved structural element 66, and the groove 42 of that corner fitting will be in register with and will abut the outer groove of the grooved structural element 66. In addition, the ribs 30 in the connecting portion 28 of the corner fitting 24 will 'be in register with and will abut the ribs 46 of the grooved structural element 44; and theribs 38 in the connecting portion 36 of that corner fitting will be in register with and will abut the ribs 67 of the grooved structural element 66.

Each of the grooves 32 and 42 in the corner fitting 24 will preferably have the same width and depth as the particular groove in the grooved structural element 44 or 66 which is contiguous with that groove. Where the thickness of each of the walls 20 and 22 is 5 inches, the groove depth will preferably be in the range of one-half to three-quarters of an inch; and the groove width will preferably be in the range of three-eighths to fiveeighths of an inch. Each of the grooves 34 and 40 in the corner fitting 24 will preferably have the same width and depth as the particular groove in the grooved structural element 44 or 66 which is contiguous with that groove. That depth will preferably be in the range of one-half to three-quarters of an inch; and the groove width will preferably be in the range of three-eighths to five eighths of an inch. FIG. 2 shows the grooves 32, 34, 40 and 42 in the comer fitting 24 as having the same depths and widths; and hence the grooves within the grooved structural elements 44 and 66 will have the same depths and widths. However, if desired, the width and depth of the groove 32 could differ from the widths and depths of one or more of the grooves 34, 40 and 42; but the width and depth of the groove 32 will preferably be the same as those of that groove of the grooved structural element 44 which is contiguous with it. Similarly, if desired, the width and depth of any of the grooves 34, 40 and 42 could differ from the depth and width of one or more of the other grooves in the corner fitting 24; but each groove in that corner fitting 24 will preferably have the same width and depth as the contiguous groove in-the grooved structural element 44 or 66.

The numeral '50 denotes a vertical element of the wall 20; and that element has the same cross section as the grooved structural element 44 in FIG. 11. As indicated by FIG. 3, the ribs of the element are denoted by the numeral 52, and the grooves of that element are denoted by the numeral 54. The ends of the element 50 are mitered by parallel mitering cuts; and the lower end of that element abuts the mitered left-hand end of the grooved structural element 44. As a result, the grooves 48 in the grooved structural element 44 abut and are in register with the grooves-54 of the element 50. Further, the ribs 460i the grooved structural element 44 abut and are in register with the ribs 52 of the-element 50. As shown by FIG. 1, the element 50 is parallel to the corner fitting 24.

The numeral 56 denotes a vertical element of the wall 20; and that element is a mirror image of the verticalelement 50. The grooved faces of those vertical elements are directed away from each other, and the plane faces of those vertical elements confront each other to define the sides of a doorway for the wall 20. The ends of the vertical element 56 are mitered; and the mitered lower end of that element abuts the mitered right-hand end of the grooved structural element 58. As a result,

the grooves, not shown, in the elements 56 and 58 will I abut and be in register with each other. Similarly, the ribs, not shown, in those elements will abut-and be in register with each other.

The numeral 60 denotes a vertical element which.

serves as the left-hand end of the wall 20; and that element has the same cross section as the grooved structural element 44 in FIG. 11. The vertical element 60 is longer than the vertical element 50; and the mitering cuts at the ends of the'former vertical element are angularly displaced, whereas the mitering cuts at the ends of the latter vertical element are parallel to each other. The mitered lower end of the vertical element 60 abuts the mitered left-hand end of the grooved structural element 58. As a result, the grooves, not shown, in the elements 58 and 68 will abut and be in register with each other.

The numeral 62 denotes a horizontal element which serves as the cap of the wall and that element has the same cross section as the grooved structural element 44 in FIG. 11. The ends of the element 62 are mitered; and the left-hand mitered end of that element abuts the mitered upper end of the vertical element 60, while the mitered right-hand end of that element abuts the mitered upper end'of the connecting portion 28 of the corner fitting 24. As a result, the grooves, not shown, in the elements 60 and 62 will abut and be in register with each other. Similarly, the ribs, not shown, in those elements will abut and be in register with each other.

The numeral 64 denotes a horizontal element of the wall 20; and that element has the same cross section as the grooved structural element 44 in FIG. 11. The ends of the element 64 are mitered by mitering cuts which incline outwardly and upwardly from the plane face of that element as shown by FIG. 1. Those mitered ends abut the mitered upper ends of the vertical elements 50 and 56, and hence the element 64 coacts with those elements to define the top and sides of the doorway in the wall 20. The grooves 63 of the element 64 will abut and be in register with the grooves 54 of the vertical element 50, and also will abut and be in register with the grooves, not shown, of the vertical element 56. Similarly, the ribs 65 of the element 64 will abut and be in register with the ribs 52 of the vertical element 50, and also will abut and be in register with the ribs, not shown, of the vertical element 56.

The elements 44, 58, 60 and 62 essentially define three sides of the frame of the wall 20; and the connecting portion 28 of the corner fitting 24 defines the fourth side of that frame. The elements 50 and 56- coact with the element 64 to define the doorway in that wall; and they also coact with the elements 44 and 58 to help define the bottom side of the frame of the wall 20. Those various elements coact with each other, with the corner fitting 24, and with the panels of that wall to strengthen and rigidify that wall. The numeral 68 denotes a vertical element which serves as the right-hand end of the wall 22; and that element has the same cross section as the grooved structural element 44 in FIG. 1 l. The ends of the vertical element 68 are mitered; and the mitered lower end of that vertical element abuts the mitered right-hand end of the bottom element 66. As a result, the grooves, not shown, in the bottom element 66 will abut and be in register with the grooves, not shown, in the vertical element 68. Similarly, the ribs 67 in the bottom element 66 will abut and be in register with the ribs, not shown, in the vertical element 68.

The numeral 70 denotes a horizontal element that serves as the cap of the wall 22; and that element has the same cross section as the grooved structuralelement 44 in FIG. 11. The ends of the horizontal element 70 are mitered; and the mitered left-hand end of that element abuts the mitered upper end of the connecting portion 36 of the corner fitting 24, while the mitered right-hand end of that element abuts the mitered upper end of the vertical element 68. Consequently, the grooves, not shown, in the horizontal element 70 will abut and be in register with the grooves 40 and 42 in the connecting portion 36 of the corner fitting 24, and also will abut and be in register with the grooves, not shown, in the vertical element 68. Similarly, the ribs, not shown, in the horizontal element 70 will abut and be in register with the ribs 38 in the connecting portion 36 of the corner fitting 24, and also will abut and be in register with the ribs, not shown, in the vertical element 68.

The elements 66, 68 and 70 define three sides of the frame of the wall 22; and the connecting portion 36 of the corner fitting 24 defines the fourth side of that frame. Those elements coact with each other, with the corner fitting 24, and with the panels of the wall 22 to strengthen and rigidify that wall. The numeral 72 de notes a panel which has a thickness that is just slightly less than the width of the groove 40 in the connecting portion 36 of the corner fitting 24; and that thickness also is just slightly less than the width of the inner grooves, not shown, in the bottom element 66 and in the upper element-70 of the wall 22. That panel can be a section of plywood, of wall board, of drywall, of decorating paneling, or the like; and, in one preferred embodiment of the present invention, that panel is 8 feet high, 4 feet wide, and three-eighths of an inch thick and thus has dimensions that are standard in the construction industry. That panel can, either in its purchased state or after it has been painted, serve as part of the interior of the. room or area which it helps bound and define. The left-hand edge of the panel 72 will extend into, and will be confined and guided by, the groove 40 of the connecting portion 36 of the corner fitting 24; and the bottom edge of that panel extends into, and will be confined and guided by, the inner groove of the bottom element 66. The upper edge of the panel 72 extends into, and will be confined and guided by, the inner groove of the upper element 70.

' The numeral 74 denotes a panel which has a thickness that is just slightly less than the width of the groove 42 in the connecting portion 36 of the corner fitting 24; and that thickness also is just slightly less than the width of the outer grooves, not shown, in the bottom element 66 and in the upper element 70 of the wall 22. That panel can be a section of plywood, of wallboard, of drywall, of decorating paneling, or the like; and, in the said one preferred embodiment of the present invention, that panel is 8 feet high, 4 feet wide, and three-eighths of an inch thick. If the surface of the wall 22, of which the panel 74 is a part, helps bound and define the interior of a room or area, that panel can, either in its purchased state or after it has been painted, serve as part of that interior. However, if the surface of the wall 22, of which the panel 74 is a part, is an exterior surface, that panel will be made so it can withstand rain, sleet, hail, snow, sunlight, heat, dirt, and the like. The lefthand edge of the panel 74 extends into, and will be confined and guided by, the groove 42 in the connecting portion 36 of the corner fitting 24, and the bottom edge of that panel extends into, and will be confined and guided by, the outer groove of the bottom element 66. The upper edge of the panel 74 extends into, and will be confined .and guided by, the outer groove in the upper portion 70.

The numeral 76 generally denotes a connector member which is a metal extension with an I-l-shaped cross section; and FIG. 10 is a perspective view of the upper end of that connector member. A web 78 of that connector member has grooves 80 and 84 extending outwardly from one face thereof, and has grooves 82 and 86 extending outwardly from the opposite face thereof. The grooves 80 and 82 are in register with each other,

and the grooves 84 and 86 are in register with each other, as shown particularly by FIGS. 2 and 10. The height of the connector member 76 is equal to the distance between the confronting surfaces of the groovedefining portions of the lower element 66 and of the upper element 70. As a result, that connector member can fit snugly between the upper surface of the lower element 66 and the lower surface of the upper element 70 of the wall 22. The groove 80 in the connector member 76 will be in register with the inner grooves, not shown, of the upper and lower elements 70 and 66; and those inner grooves are in register with the groove 40 in the connecting portion 36 of the corner fitting 24. As a result, the groove 80 will coact with those inner grooves and with the groove 40 to define an essentiallycontinuous constant-width, constant-depth groove. The groove 84 in the connector member 76 will be in register with the outer grooves, not shown, of the upper and lower elements 70 and 66; and those outer grooves are in register with the groove 42 in the connecting portion 36 of the corner fitting 24. As a result, the groove 84 will coact with those outer grooves and with the groove 42 to define an essentially-continuous constantwidth, constant-depth groove. Those essentially continuous, constant-width, constant-depth grooves are parallel to, but are transversely spaced relative to, each other. The groove 80 in the connector member 76 receives'and guides and confines the right-hand edge of the panel 72, and the groove 84 in that connector member receives and guides and confines the right-hand edge of the panel 74. As a result, the connector member 76 coacts with the connecting portion 36 of the corner fitting 24, with the lower element 66, with the upper element 70, and with the panels 72 and 74 to define a totally-enclosed space between the inner and outer surfaces of the wall 22. The engagements between the left-hand edge of the panel 72 and the groove 40 in the connecting portion 36 of the corner fitting 24, between the right-hand edge of that panel and the groove 80 in the connector member 76, and between the upper and lower edges of that panel and the grooves, not shown, in the upper and lower elements 70 and 66 will enable that panel, that corner fitting, that connector member and those elements to strengthen and rigidify the wall 22.

The grooves 80, 82, 84 and 86 in the connector member 76 can have different depths and different widths. However, the depths and widths of the grooves 80 and 82 will usually be the same, and the depths and widths of the grooves 84 and 86 will usually be the same. Importantly, the depths and widths of the grooves 80 and 82 should be the same as the depths and widths of the inner grooves of the upper and lower elements 70 and 66. Also importantly, the depths and widths of the grooves 84 and 86 should be the same as the depths and widths of the outer grooves of those upper and lower elements.

The numerals 90, 94 and 96 denote further connector members which can be identical to the connector member 76. Those connector members are verticallydirected, and the lower ends thereof rest upon the groove-defining portions of the lower element 66. The upper ends of the connector members 90, 94 and 96 underlie the groove-defining portions of the upper element 70. As shown by FIG. 1, the connector members 76, 90, 94 and 96 are disposed between and are parallel to, the corner fitting 24 and the vertical element 68 of the wall 22.

A short connector member 98, which has the same cross section as the connector member 76 of FIG. 10, is incorporated in the wall 20 in FIG. 1. That connector member is vertically-directed; and it underlies, and extends downwardly from, the upper element 62 of that wall. A similar, short connector member is vertically-directed, and it overlies and extends upwardly from the lower element 44. The connector members 98 and 100 are in vertical alignment with each other, as indicated by FIG. 1. Another similar, short connector member 102 is vertically-directed; and it underlies, and extends downwardly from, the upper element 62 of the wall 20. A further, similar short connector member 104 is vertically-directed; and it overlies and extends upwardly from the lower element 44. The connector members 102 and 104 are in vertical alignment with each other, as indicated by FIG. 1. Two shorter, similar connector members 106 and 108 are verticallydirected; and they underlie, and extend downwardly from, the upper element 62. The lower ends of the connector members 106 and 108 abut the groove-forming portions of the grooved structural element 64. The connector members 98, 100, 102, 104, 106 and 108 are disposed between, and are parallel to, the comer fitting 24 and the vertical element 60 of the wall 20.

The numeral 110 denotes a short panel which has the side edges thereof extending into, and confined and guided by, the lower portion of the groove 82 in the connector member 76 and by the lower portion of the confronting groove in the connector member 90. The lower edge of that short panel extends into the inner groove of the lower element 66. A similar short panel, not shown, which is disposed in register with but which is spaced outwardly of the panel 110, has the side edges thereof extending into, and confined and guided by, the lower portions of the confronting outer grooves of the connector members 76 and 90. A short, connector member 112, which has the same cross section as the connector member 76 of FIG. 10, is incorporated in the wall 22 in FIG. 1. That connector member is horizontallydirected, and it extends between the groovedefining portions of the connector members 76 and 90. The inner downwardly-directed groove of the connec tor-member 1 12 telescopes downwardly over the upper edge of the short panel 110; and the outer downwardlydirected groove of that connector member telescopes downwardly over the upper edge of the short panel, not shown, which is disposed in register with but which is spaced outwardly of the panel 110. The connector member 112 coacts with the lower portions of the connector members 76 and 90 and with the lower element 66 to hold the short panel 110, and the similar short panel, not shown, which is disposed in register with but which is spaced outwardly of the panel 1 10, in parallel, spaced-apart relation.

A seal 114, which is made from a resilient material such as rubber and which is U-shaped in cross section, extends around the top, sides and bottom of a rectangular glass pane 116. The closed portion of that seal extends into the mid-portion of the groove 82 in the connector member76, into the upwardly-directed inner groove of the connector member 112, and into the midportion of the inner groove, not shown, of the connector member 90. A similar seal 121 extends around the top, sides and bottom of a rectangular glass pane 122;

and the closed portion of that seal extends into the midportion of the groove 86 of the connector member 76, into the mid-portion of the confronting groove of the connector member 90, and into the upwardly-directed outer groove of the connector member 112. A short, connector member 118, which has the same cross section as the connector member 76 of FIG. 10. is incorporated in the wall 22. That connector member is horizontally directed; and it has the downwardly-directed inner groove thereof telescoped downwardly over the closed portion of the seal 114 adjacent the top of the glass pane l 16. The downwardly-directed outer groove of that connector member telescopes downwardly over the closed portion of the seal 121 adjacent the top of the glass pane 122.

A short panel 119 has the left-hand side thereof extending into, and confined and guided by, the upper portion of the groove 82 in the connector member 76, has the right-hand side thereof extending into, and confined and guided by, the upper portion of the confronting groove of the connector member 90, has the lower edge thereof extending into, and confined and guided by, the upwardly-directed inner groove of the connector member 118, and has the upper edge thereof extending into, and confined and guided by, the inner groove of the upper element 70. A corresponding short panel, not shown, has the left-hand side thereof extending into, and confined and guided by, the upper portion of the groove 86 in the connector member 76, has the right-hand side thereof extending into, and confined and guided by, the upper portion of the confronting groove in the connector member 90, has the lower edge thereof extending into, and confined and guided by, the upwardly-directed outer groove of the connector member 118, and has the upper edge thereof extending into, and confined and guided by, the outer groove of the upper element 70.

The short panel 110, the glass pane 116, and the short panel 1 l9 coact with the connector members 112 and 1 18 to serve as an essentially-continuous panel that fills the space defined by the groove 82 of the connector member 76, the confronting groove of the connector member 90 and the inner grooves of the upper and lower elements 70 and 76. Similarly, the short'panel, not-shown, which is disposed in register with but which is spaced outwardly of the panel 110, the glass pane 122, and the short panel, not shown, which is disposed is register with but which is spaced outwardly of the panel 119 coact with the connector members 112 and 118 toserve as' an essentially-continuous panel that fills the space defined by the groove 86 of the connector member 76, the confronting groove of the connector, member 90, and the outer grooves of the upper and lower elements 70 and 76. Those two essentiallycontinuous panels will coact with the connector members 76 and 90 and with the upper and lower elements 70 and 66 to strengthen and rigidify the wall 22.

The numeral 126 denotes a panel which has the sides thereof extending into, and confined and guided by, the confronting inner grooves of the connector members 90 and 94, and which has the upper and lower edges thereof extending into, and confined and guided by, the inner grooves of the upper and lower elements 70 and 66. A similar panel, not shown, which is disposed in register with but which is spaced outwardly of the panel 126, has the sides thereof extending into, and confined and guided by, the confronting outer grooves of the connector members 90 and 94, and has the lower and upper edges thereof extending into, and confined and guided by, the outer grooves of the lower and upper elements 66 and 70. Those two panels will coact with the connector members 90 and 94 and with the upper and lower elements 70 and 66 to strengthen and rigidify the wall 22. 1

The numeral 128 denotes a rectangular glass pane which has a resilient seal, not shown, like the resilient seal 114, extending around the top, sides and bottom thereof. That seal, and the sides of that glass pane, extend into, and are confined and guided by, the confronting inner grooves of the connector members 94 and 96; and that seal and the top and bottom of that glass pane, extend into, and are confined and guided by, the inner grooves of the lower and upper elements 66 and 70. A similar glass pane, not shown, which is disposed in register with but which is spaced outwardly of the glass pane 128, has a resilient seal, not shown, like the resilient seal 121, extending around the top, sides and bottom thereof. That seal, and the sides of that glass pane, extend into, and are confined and giided by, the confronting outer grooves of the connector members 94 and 96; and that seal and the top and bottom of that glass pane, extned into, and are confined and guided by, the outer grooves of the lower and upper elements 66 and 70. Thosetwo glass panes will coact tith the connector members 94 and 96 and with the upper and lower elements 70 and 66 to strengthen and rigidify the wall 22.

The numeral 130 denotes a panel which has the lefthand side thereof extending into, and confined and guided by, the right-hand inner groove of the connector member 96, has the right-hand side thereof extending into, and confined and guided by, the inner groove of the vertical element 68, and has the upper and lower edges thereof extending into, and confined and guided by, the inner grooves of the lower and upper elements 66 and 70. A similar panel, not shown, which is disposed in register with but which is spaced outwardly of the panel 130, has the sides thereof extending into, and

confined and guided by, the outer groove of the vertical element 68 and the confronting outer groove of the connector member 96, and has the lower and upper edges thereof extending into, and confined and guided by, the outer grooves of the lower and upper elements 66 and 70. The panel 130 and its outer counterpart will coact with the connector member 96, the vertical element 68 and with the upper and lower elements 70 and 66 to strengthen and rigidify the wall 22.

No nails, screws or other fasteners, and no cements, adhesives, mastics, tapes or the like are needed to hold the edges of the various panels and glass panes of the wall 22 within the grooves which receive those edges. Instead, those various grooves coact with each other to provide full support for those panels and glass panes. It should also be noted that each panel, each connector member, each glass pane, the corner fitting 24, the vertical element 68, and the lower and upper elements 66 and 70 add to the stiffness and rigidity of the wall 22. AS a result, that wall is sturdy and strong.

The numeral 132 denotes a panel which has the lower portion of the left-hand side thereof extending into, and confined and guided by, the right-hand inner groove of the connector member 100, has the upper portion of that left-hand side extending into, and confined and guided by, the right-hand inner groove of the connector member 98, and has the intermediate portion of that left-hand side extending into, and confined and guided by, the inner groove of a grooved structural element 140 which defines the right-hand side of a window-like opening in the wall 20. The cross section of the grooved structural element 140 is preferably identical to the cross section of the grooved structural element 44 of FIG. 11. The right-hand side of the panel 132 extends into, and is confined and guided by, the groove 34 of the corner fitting 24, as shown particularly by FIG. 2. The lower edge of the panel 132 entends into, and is confined and guided by, the inner groove 48 of the lower element 44; and the upper edge of that panel extends into, and is confined and guided by, the inner groove of the upper element 62.

A similar panel 133 has the lower portion of the lefthand side thereof extending into, and confined and guided by, the right-hand outer groove of the connector member 100, has the intermediate portion of that left-hand side extending into, and confined and guided by, the outer groove of the element 140, and has the upper portion of that left-hand side extending into, and confined and guided by, the right-hand outer groove of the connector member 98. The right-hand side of the panel 122 extends into the groove 32 of the corner fitting 24, as shown particularly by FIG. 2. The lower edge of the panel 133 extends into, and is confined and guided by, the outer groove 48 of the lower element 44; and the upper edge of that panel is held by the outer groove of the upper element 62.

The numeral 134 denotes a short panel which has the sides thereof extending into, and confined and guided by, the lower portions of the confronting inner grooves of the connector members 100 and 104, has the lower edge thereof extending into, and confined and guided by, the inner groove 48 of the lower element 44, and has the upper edge thereof extending into, and confined and guided by, the inner groove of a grooved structural element 136 which defines the bottom of the window-like opening in the wall 20. The cross section of the grooved structural element 136 is preferably identical to the cross section of the grooved structural element 44 of FIG. 11. A similar short panel, not shown, has the sides thereof extending into, and confined and guided by, the outer confronting grooves of the connector members 100 and 104, has the lower edge thereof extending into, and confined and guided by, the outer groove 48 of the lower element, and has the upper edge thereof extending into, and confined and guided by, the outer groove of the element 136.

The numeral 144 denotes a short panel which has the sides thereof extending into, and confined and guided by, the confronting inner grooves of the connector members 98 and 102, has the upper edge thereof extending into, and confined and guided by the inner groove of the upper element 62, and has the bottom edge thereof extending into, and confined and guided by, the inner groove of a grooved structural element 142 which defines the top of the window-like opening 50, has the upper portion of the righthand side thereof in the wall 20. The cross section of the grooved strucextending into, and confined and guided by, the lefthand inner groove of the connector member 102, has the lower portion of that right-hand side extending into, and confined and guided by, the left-hand inner groove of the connector member 104, and has the intermediate portion of that right-hand side extending into, and confined and guided by, the inner groove of a grooved structural element 138 which defines the left-hand side of the windowlike opening in the wall 20. The cross section of the grooved structural element 138 preferably is identical to the cross section of the grooved structural element 44 of FIG. 11. The lower edge of the panel 146 extends into, and is confined and guided by, the inner groove 48 of the lower element 44; and the upper edge of that panel extends into, and is confined and guided by the inner groove of the upper element 62. A similar panel 151 has the upper portion of the left-hand side thereofextending into, and confined and guided by,-the right-hand outer groove of the connec tor member 106, has the rest of that left-hand side extending into, and confined and guided by, the outer groove 54 in the vertical element 50, as shown particularly by FIG. 3, has the upper portion of the right-hand side thereof extending into, and confined and guided by, the left-hand outer groove of the connector member 102, has the lower portion of that right-hand side extending into, and confined and guided by, the lower portion of the left-hand outer groove of the connector member 104, ans has the intermediate portion of that right-hand side extending into, and confined and guided by the outer groove of the element 138. The lower edge of the panel 151 extends into, and is confined and guided by, the outer groove 48'of the lower element 44, as shown particularly by FIG. 3; and the upper edge of that panel extends into, and is confined and guided by, the outer groove of the upper element 62.

The numeral 148 denotes a short panel which has the sides thereof extending into, and confined and guided by, the confronting inner grooves of the connector members 106 and 108. The lower edge of that panel extends into, and is confined and guided by, the inner groove 63 of the element 64; and the upper edge of that panelextends into, and is confined and guided by, the inner groove of the element 62. The numerall49 denotes a similar short panel which has the sides thereof extending into and confined and guided by the confronting outer grooves of the connector members 106 and 108. The lower edge of the panel 149 extends into and is confined and guided by the outer groove 63 of the element 64; and the upper edge of that panel extends into, and is confined and guided by, the outer groove of the element 62.

The numeral 150 denotes a panel which has the upper portion of the right-hand side thereof extending into, and confined and guided by, the left-hand inner groove of the connector member 108 and has the rest of that right-hand side extending into, and confined and guided by, the inner groove of the element 56; and the left-hand side of that panel extends into, and is confined and guided by, the inner groove of the vertical element 60. The lower and upper edges of the panel 150 extend into, and are confined and guided by, the inner grooves of the elements 58 and 62. A similar panel, not shown, has the upper portion of the righthand side thereof extending into, and confined and guided by, the left-hand outer groove of the connector member 108, has the rest of that right-hand side extending into, and confined and guided by, the outer groove of the element 56, has the left-hand side thereof extending into and confined and guided by the outer groove of the element 60, and has the lower and upper edges thereof extending into, and confined and guided by, the outer grooves of the elements 58 and 62.

No nails, screws or other fasteners, and no cements, adhesives, mastics, tapes or the like are needed to hold the edges of the various panels of the wall within the grooves which receive those edges. Instead, those various grooves coact with each other to provide full support for those panels. It should also be noted that each panel, each connector member, the corner fitting 24, the vertical element 60, the elements 50, 56, 64, 136, 138, 140 and 142, the upper element 62, and the lower elements 44 and 58 add to the stiffness and rigidity of the wall 20. As a result, that wall is sturdy and strong.

The numeral 156 in FIG. 2 denotes a sturdy, L- shaped metal brace which has the vertically-directed portion thereof disposed between the exposed wall and the ribs of the element 140. A screw 158 extends through a countersunk opening in that exposed wall and seats in an opening in the vertically-directed portion of that brace. That screw and those ribs fixedly hold the element 140 against shifting or tilting relative to that L-shaped brace. The horizontally-directed portion of the L-shaped brace 156 extends between the exposed wall and the ribs of the element 136. A screw, not shown, will pass through a countersunk opening in that exposed wall and seat in an opening in the horizontally-directed portion of that L-shaped brace. That screw will coact with those ribs to prevent shifting or tilting of the element 136 relative to the L-shaped brace 156.

A similar L-shaped brace, not shown, has the vertically-directed portion thereof disposed between the upper portion of the exposed wall of the element 140 and the upper portions of the ribs of that element. A screw 155 extends through a countersunk opening in that exposed wall'and seats in an opening within that horizontally-directed portion; and that screw coacts with the ribs of that element to prevent shifting or tilting of the element 140 relative to that L-shaped brace. The horizontally-directed portion of that L-shaped brace will extend between the exposed wall and the ribs of the element 142; and a screw, not shown, will extend through a countersunk opening in that exposed wall and will seat in an opening within that horizontallydirected portion.

Similar L-shaped braces will be disposed at the upper left-hand corner and at the lower left-hand corner of the window-like opening in the wall 20. The verticallydirected portions of those L-shaped braces will be held by the exposed wall and the ribs of the element 138;

and screws, not shown, will extend through countersunk openings, not shown, in that exposed wall and seat in openings, not shown, within those vertically-directed portions. The horizontally-directed portion of the upper of those L-shaped braces will be disposed between the exposed wall and the ribs of the element 142; and a screw, not shown, will extend through a countersunk opening in that exposed wall and seat in an opening in that horizontally-directed portion. The horizontally-directedportion of the L-shaped brace adjacent the lower left-hand corner of the window-like opening in the wall 20 will be confined by the exposed wall and the ribs of the element 136; and a screw, not shown, will extend through a countersunk opening in that exposed wall and seat in an opening in that horizontallydirected portion. The L-shaped brace 156, the three L-shaped braces, not shown, adjacent the other three corners of the window-like opening in the wall 20, the screws 155 and 158, and the other six screws, not shown, coact with the elements 136, 138, 140 and 142 i to make the frame for that window-like opening sturdy and rigid. In doing so, they also help strengthen and rigidify the wall 20. v 1

The numeral 153 in FIG. 3 denotes a sturdy, L- shaped, metal-brace which has the vertically-directed portion thereof disposed between the inner face of the exposed wall of the vertical element 50 and the lefthand faces of the ribs 52 within that element. That vertically-directed portion of that brace will have a width and thickness which will enable it to readily slip into position between that wall and those ribs, and yet prevent tilting of the axis of the element 50 relative to that L-shaped brace. A screw 152 extends inwardly through a countersunk opening in the exposed wall of the element 50 and seats in an opening in the verticallydirected portion of the L-shaped brace 153; and that screw will coact with the ribs 52 to lock that L-shaped brace against shifting or tilting relative to the element 50. The horizontally-directed portion of the L-shaped brace 153 extends between the inner face of the lower wall of the element 44 and the ribs 46 within that element. A screw 154 extends upwardly through a countersunk opening in that lower wall and seats in an opening in the horizontally-directed portion of the L-shaped brace 153. That screw will coact with the ribs 46 to lock the element 44 against shifting or tilting relative to ribs 30 of that corner fitting. A screw 162 extends through a countersunk opening in that wall and seats in an opening in that vertically-directed portion of that L-shaped metal brace. That screw will coact with that wall and those ribs to lock the corner fitting 24 against shifting or tilting relative to the L-shaped brace 160. The horizontally-directed portion of that L-shaped brace will extend into the space between the bottom wall of the element 44 and the ribs 46 of that element; and a screw, not shown, will extend upwardly through a countersunk opening in that bottom wall and seat in an opening in that horizontally-directed portion. That screw will coact with those ribs to prevent shifting or tilting of the lower element 44 relative to that L-shaped brace.

Similar L -shaped braces, not shown, will be provided at the upper right-hand corner, the upper left-hand corner, and the lower left-hand corner of the wall 20 in FIG. 1. The horizontally-directed portions of the L- shaped braces, not shown, adjacent the upper left-hand and upper right-hand corners of the wall 20 will be held by theribs of the element 62 and by screws, not shown, which extend downwardly through the upper wall of that element and seat in openings in those horizontallydirected portions. The vertically-directed portion of the L-shaped brace at the upper right-hand corner of the wall 20 will be held by the upper portions of the ribs 30 of the corner fitting 24 and by a screw, not shown, which extends through a countersunk opening in the left-hand wall of the tubularsection 26 of that corner fitting and seats in an opening in that verticallydirected portion. The vertically-directed portion of the L-shaped brace at the upper left-hand corner of the wall 20 will be held by the ribs of the vertical element 60 and by a screw 159 which extends through a countersunk opening in the exposed wall of that element and seats in an opening in that vertically-directed portion. The horizontally-directed portion of the L-shaped brace, not shown, at the lower left-hand corner of the wall 20 is held by the ribs, not shown, of the lower element 58 and by a screw, not shown, which extends upwardly through a countersunk opening in the bottom wall of that element and seats in an opening in that horizontally-directed portion. The vertically-directed portion of that L-shaped brace is held by the ribs, not shown, of the vertical element 60 and by a screw 161 which extends through a countersunk opening in the exposed wall of that vertical element and seats in an opening in that vertically-directed portion.

' An L-shaped brace, not shown, will coact with the ribs of the lower element 58,'with the ribs of the element 56, and with two screws, now shown, to lock those elements against shifting or tilting relative to each other. An L-shaped brace, not shown, will coact with the ribs of the element 56, with the ribs 65 of the element 64, and with two screws, not shown, to lock the elements 56 and 64 against shifting or tilting relative to each other. An L-shaped brace 170 has the horizontally-directed portion thereof held by the'ribs 65 of the element 64 and by a screw 172 which extends upwardly through a countersunk opening in the exposed wall of that element to seat in an opening in that horizontallydirected portion. The vertically-directed portion of that L-shaped brace is held by the ribs 52 of the element 50 and by a screw 171 which extends through a countersunk opening in the exposed wall of that element and seats in an opening in that vertically-directed portion.

The L-shaped braces 153, 160 and 170 will coact with the L-shaped braces, not shown, at the upper lefthand corner, the upper right-hand corner, and the lower left-hand corner of the wall 20, with the L- shaped braces, not shown, at the upper and lower lefthand comers of the doorway, with the screws 152, 154,

159, 161, 162, 171 and 172 and with the other screws,

not shown, for those other L-shaped braces, with the corner fitting 24, and with the grooved structural elements 44, 50, 56, 58, 60, 62 and 64 to strengthen and rigidify the wall 20. Also, some of those L-shaped braces, screws and grooved structural elements strengthen and rigidify the doorway in that wall.

The numeral 164 .in FIG. 2 denotes a sturdy, L- shaped, metal brace which can be identical to the metal braces 153, 156, and in the wall 20. The vertically-directed portion of the L-shaped brace 164 is held by the ribs 38 and by a screw 166 which extends through a countersunk opening in the adjacent wall of the tubular section 26 of the corner fitting 24 and seats in an opening in that vertically-directed portion. The horizontally-directed portion of the L-shaped brace 164 is held by the ribs 67 of the lower element 66 and by a screw, not shown, which extends upwardly through a countersunk opening in the bottom wall of that elernent'and seats in an opening, not shown, in that horizontally-directed portion. The L-shaped brace 164, the screw l66,and the other screw, not shown, lock the lower element 66 against shifting or tilting relative to the comer fitting 24.

An L-shaped brace, not shown, has the verticallydirected portion thereof held by the upper portions of the ribs 38 of the comer fitting 24 and by a screw, not shown, which extends through a countersunk opening in the adjacent wall of the tubular section 26 of the corner fitting 24 and seats in an opening in that verticallydirected portion. The horizontally-directed portion of that L-shaped brace is held by the ribs of the upper element 70 and by a screw, not shown, which extends downwardly through a countersunk opening in the exposed wall of that element and seats in an opening in that horizontally-directed portion. That L-shaped brace and the screws therefor lock the upper element 70 against shifting or tilting relative to the corner fitting 24.

An L-shaped brace, not shown, has the horizontally directed portionthereof held by the ribs 67 of the lower element 66 and by a screw, not shown, which extends through a countersunk opening in the bottom wall of the element 66 to seat in an opening in that horizontally-directed portion. The vertically-directed portion of that L-shaped brace is held by ribs within the vertical element 68 and by a screw 167 which extends through I a countersunk opening in the exposed wall of that vertical element to seat inan opening in that verticallydirected portion. That L-shaped brace and the screws therefor lock the lower element 66 against shifting or tilting relative to the vertical element 68.

An L-shaped brace, not shown, has the'horizontallydirected portion thereof held by the ribs within the upper element 70 and by a screw, not shown, which extends downwardly through a countersunk opening in the exposed wall of that upper element to seat in an opening in that horizontally-directed portion. The vertically-directed portion of that L-shaped brace is held by ribs within the vertical element 68 and by a screw 173 which extends through a countersunk opening in the exposed wall of that vertical element to seat in an opening in that vertically-directed portion. That L-shaped brace and the screws therefor lock the upper element 70 against shifting or tilting relative to the vertical element 68. The L-shaped brace 164 will coact with the L-shaped braces, not shown, at the upper lefthand corner, the upper right-hand corner, and the lower right-hand corner of the wall 22, with the screws 166, 167 and 173 and with the other screws, not shown, for those other L-shaped braces, with the corner fitting 24, and with the grooved structural elements 66, 68, and 78 to strengthen and rigidify the wall 22.

the screws 166, 167 and 173 and five other screws are needed to interlock all of the grooved structural elements 66, 68, and 70 and the corner fitting 24 of the wall. All of the rest of the sturdiness and rigidity of the walls 20 and 22 is afforded by the interengagements between the L-shaped braces and the ribs and adjacent walls of the grooved structural elements and of the corner fitting and by the interengagements of the edges of the various panels and glass panes and the grooves in those grooved structural elements.

Where the outer faces of the walls 49 and 51 of the grooved structural element 44 are spaced apart inches, and where the outer faces of the side walls of the grooved structural elements 50, 56, 58, 60, 62, 64, 66, 68 and 70 also are spaced apart 5 inches, the walls and 22 of- FIG. 1 are extremely sturdy and rigid. In fact, those walls are so sturdy and rigid that they are self-supporting and do not have to have any portions thereof bolted or otherwise secured to the floor, to a ceiling, or to anything else.

The numeral .168 denotes insulation which is disposed in the space between the outer wall of the connecting portion 36 of the corner fitting 24, the web 78 of the connector member 76, and the panels 72 and 74 of the wall 22. That insulation can bev of standard and usual form, and it can be loose or it can be confined by paper orother wrappings. Similar insulation will preferably be disposed between the short panel 110 and its counterpart, between the short panel 119 and its counterpart, betweenthe panel 126 and its counterpart, between the panel 130 and its counterpart, between the panels 132 and 133, between the short panel 134 and its counterpart, between the short panel 144 and its counterpart, between the panel 146 and the panel 151,

' between the short panels 148 and 149, and between the Usually, however, some or all of the space within the tubular section 26 of the corner fitting 24 or in one or both of the'connecting portions 28 and 36 of that corner fitting, will be occupied by thin wall electrical conduits for power-supplying conductors, cables or conductors for communications purposes, and insulated water pipes. Similarly, some or all of the space in some other grooved structural elements will have thin wall electrical conduits for power-supplying conductors, cables or conductors for communication purposes, and insulated water pipes in them.

In assembling the components of the walls 20 and 22 of FIG. 1, the corner fitting 24 and the vertical elements 50, 56, and 60 can be set horizontally with the required spacing therebetween. Thereafter, the mitered right-hand end of the grooved structural element 44 can be secured to the mitered bottom of the connecting portion 28 of the corner fitting 24 by the L- shaped brace 160, by the screw 162, and by a further screw, not shown. The mitered left-hand end of that grooved structural element can be secured to the mitered bottom of the element 50 by the L-shaped brace 153 and the screws 152 and 154 ofFlG. 3. The mitered ends of the grooved structural element 48 can then be secured to the mitered bottoms of the .elements 56 and 60 by L-shaped braces, not shown, an'd'by the screw 161 and other screws, not shown. The mitered ends of the grooved structural element 64 will be secured to the mitered tops of the elements 50 and 56 by the L shaped brace 170 and screws 171 and 172 and by an L-shaped brace and two screws, not shown. The vertically-directed portion of an L-shaped brace, not shown, will be secured to the free endof the element 60 by the screw 159; and the vertically-directed portion of another L-shaped brace, not shown, will be secured to the free end of the connecting portion 28 of the corner fitting 24. The grooved structural elementsl36, 138, and 142 will have the mitered ends thereof secured together by the L-shaped brace 156 and three other L- shaped braces, and by the screws 155 and 158 and six other screws; and then the resulting window-forming frame will be set aside temporarily.

The panel 150, and the outer panel in register therewith, will then have the side edges thereof telescoped into and held by the confronting grooves of the ele-' ments 56 and 60; and the bottom edges of those panels will be telescoped into and held by the grooves of the grooved structural element 58. The left-hand grooves of the H-shaped connector member 108 will be moved into telescoping engagement with the upper ends of the right-hand edges of the panel and its counterpart;

and the bottom of that connector member will be moved into engagement with the groove-defining portions of the grooved structural element 64. The lefthand edges of the panels 148 and "149will be telescoped into and held by the right-hand grooves of the H-shaped connector member 108; and the bottoms of those panels will be'telescoped into and held by the grooves of the grooved structural element 64.

The left-hand grooves of the H-shaped connector member 106 will be moved into telescoping engagement with the right-hand edges of the panels 148 and 149; and the bottom of that connector member will be moved into engagement with the. groove-defining 'portions of the grooved structural element 64. The lower and intermediate portions of the left-hand edges of the panels 146 and 151 will be telescoped into the grooves 54 of the element 50,'the upper portions of those edges will be telescoped into the right-hand grooves of the H- shaped connector member 106, and the bottoms of those panels will be telescoped into the grooves 48 of the grooved structural element 44. The left-hand grooves of the H-shaped connector member 104 will be moved into telescoping engagement with the lower portions of the right-hand edges of the panels 146 and 151; and the bottom of that connector member will be moved into engagement with the groove-defining por: tions of the grooved structural element 44. The lefthand edges of the panel 134 and its counterpart will be telescoped into the right-hand grooves of the l-l-shaped connector member 104; and the bottoms of those panels will be telescoped into the grooves 48 of the grooved structural element 44. The left-hand grooves of the H-shaped connector member 100 will be moved into telescoping engagement with the right-hand edges of the panel 134 and its counterpart; and the bottom of that connector member will be moved into engagement 22 shown; and the mitered left-hand end of that grooved structural element will be secured in abutting engagement with the mitered bottom of the connecting porwith the groove-defining portions of the grooved struc- I tural element 44. The side edges of the panels 132 and 133 will be telescoped into the grooves 34 and 32 of the connecting portion 28 of the corner fitting 24 and into the right-hand grooves of the I-l-shaped connector member 100.

At this time, the grooves of the grooved structural element 138, of the window-forming frame, will be moved into telescoping engagement with the intermediate portions of the right-hand edges of the panels 146 and 151, and the grooves of the grooved structural element 140, of that window-forming frame, will be moved into telescoping engagement with the intermediate portions of the left-hand edges of the panels 132 and 133. The grooves of the grooved structural element 136, of that window-forming frame, will be moved into telescoping engagement with the upper edges of the panel 134 and its counterpart. The left-hand grooves of the l-l-shaped connector member 102 .will be moved into telescoping engagement with the right-hand edges of the panels 146 and 151; and the bottom of that connector member will be moved into engagement with the groove-defining portions of the grooved structural element 142 of that'window-forming frame. The righthand grooves of the H-shaped connector member 98 will be moved into telescoping engagement with the upper portions of the left-hand edges of the panels 132 and 133; and the bottom of that connector member will be moved into engagement with the groove-defining portions of the grooved structural element 142. The side edges of the panel 144 and its counterpart will be telescoped into the confronting grooves of the connector members 98 and 102; and the bottom edges of those panels will be telescoped into the grooves of the grooved structural element 142 of that windowforming frame.

Countersunk openings, not shown, will be formed in the upper wall of the grooved structural element 62; and those openings will be in register with the openings in the horizontally-directed portions of the L-shaped braces at the free ends of the corner fitting 24 and of vertical element 60. The grooves of that grooved structural element will then be telescoped downwardly over the upper edges of the panel 150 and its counterpart, of the panels 148 and 149, of the panels 146 and 151, of the panel 144 and its counterpart, and of the panels 132 and 133. Thereafter, two self-tapping metal screws, not shown, will be passed downwardly through those countersunk openings and seated in the openings in those horizontally-directed portions of those L- shaped braces. The resulting wall 20 will be sturdy and rigid.

The vertically-directed portion of the L-shaped brace 164 will be secured to the lower end of the inner wall of the connecting portion 36 of the corner fitting 24 by the screw 166; and the vertically directed portion of another L-shaped brace, not shown, will be secured to the upper end of that wall by a screw, not shown. The mitered right-hand end of the grooved structural element 66 will have the horizontally-directed portion of an L- shaped brace, not shown, secured to it by a screw, not

tion 36 of the corner fitting 24 by a screw, not shown. That grooved structural element will besuitably held in vertical position during and after the time the mitered left-hand end thereof is being secured to the mitered bottom of the connecting portion 36 of the corner'fitting 24. Thereafter, the wall 20 can be tilted bodily upwardly to the vertical position of FIG. 1, and, as it is so tilted, the grooved structural element 66 will be lowered to the horizontal position of FIG. 1. One or more props will then be used to hold that wall in vertical position.

The panels 72 and 74 will have the left-hand edges thereof telescoped into the grooves 40 and 42 of the connecting portion 36 of the corner fitting 24; and the bottoms of those panels will be telescoped into the grooves of the grooved structural element 66. The grooves and 84 of the H-shaped connector member 76 will be telescoped over the right-nand edges of the panels 72 and 74; and the bottom of that Hshaped connector member will be moved into engagement with the groove-defining portions of the grooved structural element 66. The left-hand edges of the panel 110 and its counterpart will be telescoped into the grooves 82 and 86 of the H-shaped connector member76; and the bottom edges of those panels will be telescoped into the grooves of the grooved structural element 66. The lower portions of the left-hand grooves of the H-shaped connector member 90 will be telescoped over the righthand edges of the panel and its counterpart; and the bottom of that H-shaped connector member will be moved into engagement with the groove-defining portions of the grooved structural element 66. The lower grooves of the l-l-shaped connector member 112 will be telescoped over the upper edges of the panel 110 and its counterpart.

The seal 114 will be fitted around the top, bottom and sides of the glass pane 116; and the seal 121 will be fitted around the top, bottom and sides of the glass pane 122. Thereupon, the seal-encased sides of the glass pane 116 will be telescoped into the groove 82 of the H-shaped connector member 76 and into the confronting groove of the H-shaped connector member 90. The seal-encased bottom of that glass pane will be telescoped into the upper inner groove of the H-shaped connector member 112. The seal-encased sides of the glass pane 122 will be telescoped into the groove 86 of the l-l-shaped connector member 76 and into the confronting groove of the H-shaped connector member 90. The seal-encased bottom of that glass pane will be telescoped into the upper outer groove of the H-shaped connector member 112. The lower, inner groove of the H-shaped connector member 118 will be telescoped over the seal-encased top of the glass pane 116; and the lower outer groove of that H-shaped connector memberwill be telescoped over the seal-encased top of the glass pane 122; The side edges of the panel 119 and its counterpart will be telescoped into the grooves 40 and 42 of the H-shaped connector member 76 and into the confronting grooves of the l-l-shaped connector member 90. The bottoms of those panels will be telescoped into the upper grooves of the H-shaped connector member 118.

The left-hand edges of the panel 126 and its counterpart will be telescoped into the right-hand grooves of 

1. A wall that has an aperture therein and that includes an elongated base member, an elongated top member disposed above and in vertical registry with said base member, a vertically-directed member extending between said base member and said top member, a second vertically-directed member extending between said base member and said top member, said second vertically-directed member being laterally displaced from the first said verticallydirected member, a spacing member extending between said base member and said top member, said spacing member being laterally displaced from said first said vertically-directed member and from said second vertically-directed member, said members being frame-defining members which coact to define a frame for said wall, a plurality of aperture-defining members which coact to define said aperture for said wall, said base member having a horizontally-directed web, said top member having a horizontallydirected web parallel to said web of said base member, said first said vertically-directed member having a vertically-directed web which is normal to said web of said base member and which also is normal to said web of said top member, said second verticallydirected member having a vertically-directed web which is parallel to said web of said first said vertically-directed member and which is normal to said web of said base member and which also is normal to said web of said top member, said spacing member having a web, each of said aperture-defining members having a web, a plural-arm locking member having one arm thereof abutting one portion of said web of said base member and having another arm thereof abutting one portion of said web of said first said vertically-directed member, a second plural-arm locking member having one arm thereof abutting a second portion of said web of said base member and having another arm thereof abutting one portion of said web of said second verticallydirected member, a third plural-arm locking member having one arm thereof abutting one portion of said web of said top member and having another arm thereof abutting a second portion of said web of said first said vertically-directed member, a fourth pluralarm locking member having one arm thereof abutting a second portion of said web of said top member and having another arm thereof abutting a second portion of said web of said second vertically-directed member, a fifth plural-arm locking member having one arm thereof abutting one portion of said web of said spacing member and having another arm thereof abutting a third portion of said web of said base member, a sixth plural-arm locking member having one arm thereof abutting a second portion of said web of said spacing member and having another arm thereof abutting a third portion of said web of said top member, further plural-arm locking members having arms thereof abutting said webs of said aperture-defining members, each of said aperture-defining members and some of said frame-defining members having elongaTed, parallel, transversely-spaced grooves, said elongated, parallel, transversely-spaced grooves of said aperture-defining members facing outwardly and away from said aperture, said elongated, parallel, transversely-spaced grooves of said some frame-defining members facing inwardly of said frame, said elongated, parallel, transversely-spaced grooves of said aperture-defining members confronting and being in register with said transversely-spaced grooves in a plurality of said some frame-defining members, each of said transversely-spaced grooves in said aperture-defining members having substantial portions of the confronting surfaces of the walls thereof parallel to each other, said transverselyspaced grooves in contiguous members of said some frame-defining members being aligned and in communication with each other, said transversely-spaced grooves in contiguous members of said aperture-defining members being aligned and in communication with each other, fasteners which are positively and mechanically secured to said first said, second, third, fourth, fifth and sixth locking members, further fasteners which are positively and mechanically secured to said further locking members, a plurality of panels which coact to define a plane and which have edges thereof extending into and held by one of said transverselyspaced grooves in said some frame-defining members, a second plurality of panels which coact to define a second plane and which have edges thereof extending into and held by the second of said transversely-spaced grooves in said some frame-defining members, at least one of said panels of the first said plurality of panels having an edge thereof extending into and held by one of said transversely-spaced grooves in at least one of said aperture-defining members, at least one of said panels of said second plurality of panels having an edge thereof extending into and held by the second of said transversely-spaced grooves in said one of said aperture-defining members, the panels of said first said plurality of panels coacting to define a first surface for said wall, the panels of said second plurality of panels coacting to define a second surface for said wall, said aperturedefining members and said frame-defining members coacting with said first said and said second plurality of panels to bound and define an insulating space which is located within said wall and which is intermediate said aperture and the outer periphery of said frame, said top member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said top member to define transversely-spaced slots that receive and confine both side edges of said one arm of said third locking member and of said one arm of said fourth locking member and of said other arm of said sixth locking member, whereby said third locking member engages and is secured to and confined by said top member and whereby said fourth locking member engages and is secured to and confined by said top member and whereby said sixth locking member engages and is secured to and confined by said top member, said first said vertically-directed member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said first said vertically-directed member to define transverselyspaced slots that receive and confine both side edges of said other arm of said third locking member and of said other arm of said first said locking member, whereby said third locking member engages and is secured to and confined by said first said vertically-directed member and whereby said first said locking member engages and is secured to and confined by said first said vertically-directed member, said third locking member coating with one of the first said fasteners and with said ribs on said top member to provide three transversely-spaced points of securement between said top member and said third locking member to rigidly lock said third locking member to said top member and thereby fix the location of said first said vertically-directed member relative to said top member, said second verticallydirected member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said second vertically-directed member to define transversely-spaced slots that receive and confine both side edges of said other arm of said fourth locking member and of said other arm of said second locking member, whereby said fourth locking member engages and is secured to and confined by said second vertically-directed member and whereby said
 2. A wall that includes an elongated base member, an elongated top member disposed above and in vertical registry with said base member, a vertically-directed member extending between said base member and said top member, a second vertically-directed member extending between said base member and said top member, said second vertically-directed member being laterally displaced from the first said vertically-directed member, said members being frame-defining members which coact to define a frame for said wall, said base member having a horizontally-directed web, said top member having a horizontally-directed web parallel to said web of said base member, said first said vertically-directed member having a vertically-directed web which is normal to said web of said base member and which also is normal to said web of said top member, said second vertically-directed member having a vertically-directed web which is parallel to said web of said first said vertically-directed member and which is normal to said web of said base member and which also is normal to said web of said top member, a plural-arm locking member having one arm thereof abutting one portion of said web of said base member and having another arm thereof abutting one portion of said web of said first said vertically-directed member, a second plural-arm locking member having one arm thereof abutting a second portion of said web of said base member and having another arm thereof abutting one portion of said web of said second vertically-directed member, a third plural-arm locking member having one arm thereof abutting one portion of said web of said top member and having another arm thereof abutting a second portion of said web of said first said vertically-directed member, a fourth plural-arm locking member having one arm thereof abutting a second portion of said web of said top member and having another arm thereof abutting a second portion of said web of said second vertically-directed member, some of said frame-defining members having elongated, parallel, transversely-spaced grooves, said elongated, parallel, transversely-spacEd grooves of said some frame-defining members facing inwardly of said frame, said transversely-spaced grooves in contiguous members of said some frame-defining members being aligned and in communication with each other, fasteners which are positively and mechanically secured to said first said, second, third and fourth locking members, a plurality of panels which coact to define a plane and which have edges thereof extending into and held by one of said transversely-spaced grooves in said some frame-defining members, a second plurality of panels which coact to define a second plane and which have edges thereof extending into and held by the second of said transversely-spaced grooves in said some frame-defining members, the panels of said first said plurality of panels coacting to define a first surface for said wall, the panels of said second plurality of panels coacting to define a second surface for said wall, said frame-defining members coacting with said first said and said second plurality of panels to bound and define an insulating space which is located within said wall, said first said vertically-directed member being disposed intermediate the ends of said wall, said first said vertically-directed member having elongated, vertically-directed, parallel, transversely-spaced flanges at the opposite edges of said vertically-directed web thereof, one of said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member extending outwardly beyond both faces of said vertically-directed web of said first said vertically-directed member, the other of said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member also extending outwardly beyond both faces of said vertically-directed web of said first said vertically-directed member, said one of said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member receiving and helping hold one portion of one panel of said first plurality of panels, the other of said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member receiving and helping hold one portion of one panel of said second plurality of panels, the other of said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member receiving and helping hold one portion of one panel of said second plurality of panels, said top member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said top member to define transversely-spaced slots that receive and confine both side edges of said one arm of said third locking member and of said one arm of said fourth locking member, whereby said third locking member engages and is secured to and confined by said top member and whereby said fourth locking member engages and is secured to and confined by said top member, said first said vertically-directed member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other and which are normal to said elongated, vertically-directed, parallel, transversely-spaced flanges of said first said vertically-directed member, said ribs being parallel to but spaced short distances away from said web of said first said vertically-directed member to define transversely-spaced slots that receive and confine both side edges of said other arm of said third locking member and of said other arm of said first said locking member, whereby said third locking member engages and is secured to and confined by said first said vertically-directed member and whereby said first said locking member engages and is secured to and confined by said first said vertically-directed member, said third locking member coacting wiTh one of said fasteners and with said ribs on said top member to provide three transversely-spaced points of securement between said top member and said third locking member to rigidly lock said third locking member to said top member and thereby fix the location of said first said vertically-directed member relative to said top member, said second vertically-directed member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said second vertically-directed member to define transversely-spaced slots that receive and confine both side edges of said other arm of said fourth locking member and of said other arm of said second locking member, whereby said fourth locking member engages and is secured to and confined by said second vertically-directed member and whereby said second locking member engages and is secured to and confined by said second vertically-directed member, said fourth locking member coacting with one of said fasteners and with said ribs on said top member to provide three transversely-spaced points of securement between said top member and said fourth locking member to rigidly lock said fourth locking member to said top member and thereby fix the location of said second vertically-directed member relative to said top member, said base member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said base member to define transversely-spaced slots that receive and confine both side edges of said
 3. A wall that includes an elongated base member, an elongated top member disposed above and in vertical registry with said base member, a vertically-directed member extending between said base member and said top member, a second vertically-directed member extending between said base member and said top member, said second vertically-directed member being laterally displaced from the first said vertically-directed member, a plurality of spacing members extending between said base member and said top member, said spacing members being laterally displaced from said first said vertically-directed member and from saId second vertically-directed member, said members being frame-defining members which coact to define a frame for said wall, said base member having a horizontally-directed web, said top member having a horizontally-directed web parallel to said web of said base member, said first said vertically-directed member having a vertically-directed web which is normal to said web of said base member and which also is normal to said web of said top member, said second vertically-directed member having a vertically-directed web which is parallel to said web of said first said vertically-directed member and which is normal to said web of said base member and which also is normal to said web of said top member, each of said spacing members having a web, a plural-arm locking member having one arm thereof abutting one portion of said web of said base member and having another arm thereof abutting one portion of said web of said first said vertically-directed member, a second plural-arm locking member having one arm thereof abutting a second portion of said web of said base member and having another arm thereof abutting one portion of said web of said second vertically-directed member, a third plural-arm locking member having one arm thereof abutting one portion of said web of said top member and having another arm thereof abutting a second portion of said web of said first said vertically-directed member, a fourth plural-arm locking member having one arm thereof abutting a second portion of said web of said top member and having another arm thereof abutting a second portion of said web of said second vertically-directed member, further plural-arm locking members, each of said further plural-arm locking members having one arm thereof abutting one portion of the web of one of said spacing members and having another arm thereof abutting a portion of said web of said base member, still further plural-arm locking members, each of said still further plural-arm locking members having one arm thereof abutting one portion of the web of one of said spacing members and having another arm thereof abutting a portion of said web of said top member, some of said frame-defining members having elongated, parallel, transversely-spaced grooves, said elongated, parallel, transversely-spaced grooves of said some frame-defining members facing inwardly of said frame, said transversely-spaced grooves in contiguous members of said some frame-defining members being aligned and in communication with each other, fasteners which are positively and mechanically secured to said first said, second, third, fourth, further, and still further locking members, a plurality of panels which coact to define a plane and which have edges thereof extending into and held by one of said transversely-spaced grooves in said some frame-defining members, a second plurality of panels which coact to define a second plane and which have edges thereof extending into and held by the second of said transversely-spaced grooves in said some frame-defining members, the panels of said first said plurality of panels coacting to define a first surface for said wall, the panels of said second plurality of panels coacting to define a second surface for said wall, said frame-defining members coacting with said first said and said second plurality of panels to bound and define an insulating space which is located within said wall, said top member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said top member to define transversely-spaced slots that receive and confine both side edges of said one arm of said third locking member and of said one arm of said fourth locking member and of said other arms of said still further locking members, whereby said third locking member engages and is secured to and confined by said top member and whereby said fourth locking member engages and is secured to and confined by said top member and whereby said still further locking members engage and are secured to and confined by said top member, said first said vertically-directed member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said first said vertically-directed member to define transverse-spaced slots that receive and confine both side edges of said other arm of said third locking member and of said other arm of said first said locking member, whereby said third locking member engages and is secured to and confined by said first said vertically-directed member and whereby said first said locking member engages and is secured to and confined by said first said vertically-directed member, said third locking member coacting with one of said fasteners and with said ribs on said top member to provide three transversely-spaced points of securement between said top member and said third locking member to rigidly lock said third locking member to said top member and thereby fix the location of said first said vertically-directed member relative to said top member, said second vertically-directed member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said second vertically-directed member to define transversely-spaced slots that receive and confine both side edges of said other arm of said fourth locking and of said other arm of said second locking member, whereby said fourth locking member engages and is secured to and confined by said second vertically-directed member and whereby said second locking member engages and is secured to and confined by said second vertically-directed member, said fourth locking member coacting with one of said fasteners and with said ribs on said top member to provide three transversely-spaced points of securement between said top member and said fourth locking member to rigidly lock said fourth locking member to said top member and thereby fix the location of said second vertically-directed member relative to said top member, said base member having elongated ribs thereon which are spaced apart but which are in register with each other and which extend toward each other, said ribs being parallel to but spaced short distances away from said web of said base member to define transversely-spaced slots that receive and confine both side edges of said one arm of the first said locking member and of said one arm of said second locking member and of said other arms of said further locking members, whereby said second locking member engages and is secured to and confined by said base member and whereby said first said locking member engages and is secured to and confined by said base member and whereby said further locking members engage and are secured to and confined by said base member, said first said locking member coacting with one of said fasteners and with said ribs on said base member to provide three transversely-spaced points of securement between said base member and said first said locking member to 